Check out our official Devpost submission here: https://devpost.com/software/codewatch-wm83fl
Inspiration
The fastest way to improve as a programmer is through high-stakes competition—whether that is technical interviews, demanding engineering roles, or competitive programming contests. However, all of these share one major flaw: waiting.
Weekly contests only happen once a week, major competitions happen monthly or annually, and beginners breaking into the field rarely get daily interview practice. Inspired by the fast-paced matchmaking of Overwatch, we wanted to eliminate the wait time and let developers sharpen their skills on demand.
Our Philosophy: Blue vs. Red
Great code isn't written in isolation; it's proven through competition. Programming is about thinking faster, adapting smarter, and staying calm under pressure. We built CodeWatch around a core visual and competitive rivalry:
• The Blue Character (You): Represents intelligence, precision, creativity, and clean code. Blue embodies the developer who anticipates edge cases and outsmarts the competition.
• The Red Demon (Your Opponent): Represents chaos, unexpected challenges, and the constant threat of being outperformed. Red is always lurking, waiting to exploit a bug or pull ahead.
Victory comes down to pure skill. Don't just write code—compete with it, outsmart your opponent, and win the duel.
What CodeWatch Does
CodeWatch brings instant, on-the-spot matchmaking to coding:
• 1v1 Coding Duels: Players queue up and immediately face off against another developer in a real-time coding battle.
• The Cyber-Range: For developers interested in cybersecurity, the Cyber-Range lets players write defensive code designed to withstand attacks. If your defenses hold, you earn rewards. If another player breaks through your code, they steal your resources.
Instead of waiting days or weeks for the next scheduled contest, developers can jump into live matches whenever they want to practice.
How We Built It
We combined modern web frameworks with real-time code execution tools to handle matchmaking, sessions, and live judging:
• Frontend: Built with React and TypeScript for a responsive, game-like user interface.
• Backend & Database: Powered by Python (FastAPI) and Node.js. FastAPI handles our core routes, rate limits, and compiling logic while communicating with Node to read submission data. We used SQLModel alongside SQLAlchemy to manage concurrent match sessions, user sessions, and judge sessions, paired with JWT for authentication and database state handling.
• Code Execution: Integrated Judge0 and external APIs to serve problem sets and deliver reliable, real-time execution feeds to both players during a match.
• Infrastructure & AI Tooling: Deployed on DigitalOcean using Docker. We also leveraged Claude AI and Claude Code throughout the hackathon to rapidly prototype frontend iterations, debug server configurations, and accelerate feature development.
Challenges We Ran Into
• WSL2 & Judge0 Compatibility: Running Judge0 locally on a Windows machine using WSL2 caused system-level restrictions that blocked execution logic. Moving our testing environment onto a dedicated DigitalOcean server resolved the bottleneck and allowed us to properly test live PvP matches.
• Recursive Matchmaking Bugs: Our JavaScript player-finder queue initially suffered from a bug where the matchmaking function recursively called itself twice, hitting execution limits and abruptly dropping players from the queue. Refactoring the queue state fixed the loop and stabilized matchmaking.
• Start up failures: With each deployment, there's risk of failure. For instance, deploying our new Agent Prompt feature, a use-minimal-tokens competition, we had to migrate our server to fit its needs. Additionally, the prompt feature didn't work for some commits, which we thankfully fixed by connecting both the local and server's database to the Agent.
• Scope: To avoid overengineering our project, the teams decided to implement our ideas but note them as "coming soon" (or "incomplete"). For instance, the game modes that are 2v2 or higher are behind this wall. However, this choice is to showcase the plans we have for this application after the event.
Accomplishments We're Proud Of
Getting Version 1 live and watching two players successfully match, write code, and get judged in real time on our DigitalOcean server was a huge milestone. Our team also divided responsibilities cleanly across frontend, backend, and infrastructure, making code integration and debugging much smoother than expected.
What We Learned
This was our first time building a gamified developer platform. Along the way, we gained hands-on experience with real-time app deployment, Docker containerization, collaborative Git workflows, and managing concurrent session states under pressure.
What's Next for CodeWatch
During our research, we were surprised to find that an instant-queue, 1v1 PvP coding platform like this didn't really exist yet. Based on the momentum from our initial build, we plan to open-source CodeWatch so developers across software engineering and cybersecurity can contribute new game modes, problem sets, and features.
Try it here:
https://codewatch.us/
